Question

Which of the following carbanion expected to be most stable?

• A. $p - NO_{2}C_{6}H_{4}CH_{2}$
• B. $o - NO_{2}C_{6}H_{4}\overset{-}{C}H_{2}$
• C. $o - CHOC_{6}H_{4}CH_{2}$
• D. $p - CHOC_{6}H_{4}CH_{2}$

Answer 1

Answer: (B)

$o - NO_{2}C_{6}H_{4}\overset{-}{C}H_{2}$

Answer 2

: Carbanions are stabilized by electron with drawing groups. - $NO_{2}$ is stronger electron withdrawing group as compared to – CHO. At ortho – position, the effect is more pronounced.